Local media players are shying away from ProSieben because of tough anti-cartel legislation. Earlier this year, Berlin-based publishing giant Axel Springer withdrew a bid for ProSieben after German media authorities had warned they would likely block the deal.

But Germany has no restrictions on foreign ownership of media assets. Indeed, ProSieben is currently controlled by an investment consortium led by U.S. mogul Haim Saban.

If some of Germany's leading politicos have their way, that could change. On Sunday, German culture minister Bernd Neumann called for "a new discussion on media concentration laws" in light of the ProSieben auction.

"We have to have a discussion (as to) whether it is sensible that there are upper limits for German bidders that don't exist for foreign companies," Neumann said.

The political debate was sparked by news last week that Silvio Berlusconi's Mediaset could bid for ProSieben (HR 11/8).

Although Mediaset has since been removed from the list of potential bidders, the idea that the former Italian prime minister could control the country's largest commercial broadcaster has led many to question Germany's liberal foreign-ownership laws.

Kurt Beck, leader of Germany's Social Democratic party, has called for a new law that would cap foreign ownership of German broadcasters at 25%.

It is unclear whether political interference could block a deal on ProSieben. According to sources near the negotiations, several foreign private equity companies have submitted bids for the German TV group, including KKR, Permira, Apax and Goldman Sachs.